1. Field of the Invention
This invention relates in general to respiratory systems and in particular to a new and useful device for enhancing breathing and artificial respiration wherein the inspiration phases are repeated periodically several to many times within the time constant of the lungs and a respiratory gas supply is controlled by pressure which is sensed in a connection to the trachea.
2. Description of the Prior Art
The known respirators are controlled according to the breathing rhythm, whereby the respiration frequency can range from 1 to 70/min. The apparatus according to the invention will enhance or replace the breathing by the supply of respiratory gas to the lungs with respiration frequencies which can be substantially higher than the breathing frequency, using respiration frequencies of up to 600/min with timing ratios of inspiration time to expiration time of 3:1 to 1:5. These are achieved by pneumatic controls composed of static-logic control elements.
A respirator controlled by fluidic elements is known, where the respiration is supplied with inspiration phases repeated periodically several to many times within the time constant of the lungs. The inspiration phases are controlled over timing relays; the pressure switch, controlled by the pressure in the trachea, can end the inspiration phase after attaining a set maximum pressure, and switch to expiration.
This known apparatus uses pneumatic wall jet elements which have a high gas consumption. The respiration frequencies cannot be set directly; they must be computed over the separately set inspiration and expiration time. (Klain M, Smith RR: Fluidic Technology, Anaesthesia, 31:750, 1976).
An apparatus for enhancing breathing and/or artificial respiration is known which consists of a chamber to be set under excess pressure, to which is connected a tracheal tube. This chamber is set under excess pressure over a blow-in tube connected to the respiratory gas supply. The respiratory gas is supplied through a jet pipe arranged on the inner wall parallel to the tube axis. The chamber has an opening to the outside opposite the connection of the tracheal tube. This opening is closed by the injector effect of the blow-in tube.
The respiratory gas supplied through the jet pipe is supplied in the breathing rhythm by a control device equipped with fluidic elements. The pressure-dependence is achieved over a sensor line which is connected in a distance behind the blow-in opening of the jet pipe.
The fluidic elements used in the control device cause a high gas consumption (DOS 26 03 063). The object of the invention is to provide a respiration control with a low gas consumption adapted to the apparatus. The respiration frequency is to be set directly with a setting element without changing the timing ratio inspiration/expiration.